Dear Tony Robinson,
The idea of using those ratios came to Dr Albrecht´s mind after extracting the bases ( cations with an alcaline reaction like Na, K, Ca and Mg ) from the humus portion of the soil ( Kinsey´s personnal communication ). He then thought : Why not expand those ratios to all CEC which is formed basically by colloidal clay and humus ? With some electrical and chemical manipulations Dr Albrecht have managed to extract all the bases from a large colloidal clay portion previously gathered and substitute them by H+. He then did back all sort of base saturations and combinations and came to the conclusion that those ratios he found in the humus portion were indeed the ones that would give maximum plant growth with quality ( mineral content, density, etc...) The questions was : Is there different CEC´s to different crops ? The answer is yes. Bananas, Pineapples and grapes for instance as well as woody plants requires a higher K base saturation. They require 7.5% of K as oposed to from 3 to 5% for most of the crops. However, Calcium and Magnesium remain the same . Are there different CEC for different soil pHs ? The answer is No. Once you saturate your CEC with say 65% of calcium 15% of Magnesium and 3 to 5% of Potassium the pH goes to where it should be that is close to 6.3 to 6.5 simply bacause what is left in the CEC for Hydrogen which would be around 15% would always give you that same pH reading. Are there CEC ratios for different soils ? The answer is Yes. Sandy soils are loose by nature and we do not want to increase this characterist by having a higher base saturation with calcium. According to Kinsey, in those soils a more conservative figure, i.e. 60% is recommended with 20% of Magnesium that do have an aggregation effect in the soil whereas in very heavy clay soils that are sticky by nature we can have as high as 68% of Calcium and only 12% of Magnesium. In my oppinion you can choose any figure from those two extremes to match your soil conditions. A CEC of 4 would be a good example of a sandy soil and a CEC of 20 would be a good example of a heavy clay soil. If you have a heavy clay soil as you said you will need then 68% of Calcium, 12% Magnesium. What is your CEC by the way ? I need to know also your humus content. Tell me any figure regarding Ca, Mg, K, Na and also your micro nutrient levels such as Fe, Mn, Zn, Cu and Boron. Once your soil is put in the Albrecht ratios a special attention has to be given to the micronutrients. Knowing those numbers it allows me to give you some suggestions. However, I might warn you that the numbers vary from lab to lab and a 65% calcium reading from one lab may not be the same 65% figure from another lab. Knowing that limitation we can take my advise as a guideline and not as any absolute figure that would need to be strickly followed. Jose > Hi Lloyd, Jose, Tim > > I am part way through reading Albrecht vol 1 and have some questions. > > 1. Are there different CEC ratios for different crops? > > 2 Are there different CEC ratios for different soil Ph? > > 3 Are there different CEC ratios for different soils? > > I grow ornamental crops ie perennial flowers and all year round > harvesting of cut ferns. > I have a heavy clay soil and all my crops require a ph of between 5-6 > > In vol 1 Albrecht is mainly discussing grain and lequme crops that grow > in a ph range 6-7. As i have been reading the above qeustions have > come to mind. Any thoughts please.I am working with soils that have been > thrashed to death after 20 years of chemical farming. All my crops are > perenials and take 2 years to replace and bring into full production > again. Progress is very slow and i still have a very large morgage to > clear before i achieve a level of sustainability. > > Thankyou > Tony Robinson > Rambler FLowers > New Zealand >
